Native Instruments has already made significant inroads in the desktop-music market with Reaktor and other products. Now the company has produced yet another remarkable piece of software. Spektral Delay 1.0, which runs as a standalone application and a VST plug-in, takes the concept of frequency-dependent delays and turns it into a powerful sound-processing environment.

Like all of Native Instruments' products, Spektral Delay runs without dedicated audio hardware. Its flexibility and low cost come with a price, though: you need a serious computer to take full advantage of the program.

I tested the standalone application and the VST plug-in on a Power Computing clone with a 400 MHz G3 processor card with 272 MB of RAM. With the program looping a sound file and the modulation features engaged, the response of the program's controls was sluggish and unwieldy, bordering on unusable. (Keep in mind that the memory architecture on an upgrade card is slower than that on a new computer.) But the actual sound output remained excellent. On a G4/450 MHz, the program's performance was noticeably better, though occasionally the mouse response was still frustratingly slow.

Fortunately, you can tweak Spektral Delay's settings in a number of places to optimize performance on your hardware. As is usual with plug-ins, the faster the computer, the happier you'll be with the program's performance.

Spektral Delay supports standard MME, DirectX, and ASIO drivers under Windows or Sound Manager and ASIO on the Mac. (Real Time AudioSuite support is under development, according to the manufacturer.) The program ships with a nicely printed softcover manual in four languages (English, German, French, and Spanish). In general, it communicates most of what's needed to use the program effectively. However, I wish more were included about the program's MIDI control features, specifically more about using Spektral Delay with Open Music System (OMS) on the Mac via the IAC bus.

LAY IT OUT

Spektral Delay is laid out in a fairly straightforward manner. All controls are presented in one large window, with the three main parameter controls (Filter, Frequency, and Feedback) occupying much of the space (see Fig. 1). The Modulation controls appear along the top of the window and the file-related ones along the bottom. Gain and Wet/Dry Mix controls are in the upper left corner, as is a preset-management section for storing and recalling user-created parameter presets.

The program's three main controls are presented as Matrix Editors, which are rectangular edit windows where horizontal (x) and vertical (y) mouse movements control two independent parameters. In the Filter editor, x controls the amplitude of the frequency selected by the y movement. In the Frequency editor, x is delay time and y is frequency, and in the Feedback editor, x is feedback amount and y is frequency.

Each of the three editors provides a left and a right pane for stereo signals, but they can be unlinked to allow independent processing of each channel for each matrix, which is crucial. Some of the most interesting results came from creating a stereo-like effect by using subtly or drastically different settings for the left and right channels in any or all of the three editors. Each editor can also be bypassed, if desired.

The program's overall layout makes sense but can be a bit hard to get used to. That's because the horizontal (x) values increase as the cursor moves from left to right, which causes a solid graphic fill to be displayed in the cursor's wake. However, the background behind the fill is a striped pattern, which plays a trick on the eyes and can be confusing: it looks as though the background is actually the fill. I wish that the background and fill patterns were swapped for the sake of clarity.

To the left of the main controls is the Input Modulation section, which offers several preset modulation algorithms that further mangle the sonic transformations controlled by the rest of the program. The algorithms have colorful names such as Deterioration, Jello Mold, Phase Blaster, Pitch Roll, and Lime Twist, and make for good starting points (the manual describes the function of each algorithm). I particularly liked Phase Blaster for its watery, shifting quality and Deterioration for its mangling effect. (You can hear examples of the algorithms at the EM Web site.)

The Input Modulation section provides three knobs for independently controlling the parameters of the left and right channels. The knobs can be linked, and their functions change with the selected algorithm.

At the extreme left and right sides of the main window are the input and output Sonogram windows. Although not essential to the program's operation, those displays provide a continuously scrolling graphic representation of the spectral content of the sound going through the program. Native Instruments says the Sonogram windows don't impact the program's performance.

SPEKTRAL COMPONENTS

You'll find other transformation possibilities in the Editor panel, which lets you apply mathematical functions to the various edit matrices (see Fig. 2). For example, the Quantize function, which applies only to the Delay matrix, allows edit gestures to be quantized to the current tempo grid (if one is active). Other functions include sine, triangle, sawtooth up, sawtooth down, and random wave shapes. Each shapes the selected area of the matrix being edited if a selection exists or the whole matrix if no area has been selected. Selections are made using the Marquee icon next to Spektral Delay's pencil tool.

Spektral Delay also has a single LFO that you can apply independently to three destination parameters simultaneously. Each LFO instance can have a different modulation depth. The available destination choices cover all possibilities of x and y modulation of each of the three matrices, so many radical effects are possible. For instance, setting the LFO to a slow sine wave and modulating high-frequency attenuation and low-frequency feedback positively while modulating midband delay time negatively yields a complex shifting timbral result on virtually any sustained sound. The effect is rather like an instant sound sculpture. Available LFO wave shapes are the same as the wave functions.

The Delay Matrix offers a range of maximum delay-time settings, as long as 3, 6, or 12 seconds. Those require 5, 9, and 17 MB of RAM respectively. The number of analysis bands you use determines the maximum resolution for each setting. Five settings control the number of analysis bands: 64, 128, 256, 512, and 1,024. Higher settings require more CPU power. However, more analysis bands do not automatically produce the best sound; the results depend largely on the sound being processed.

Spektral Delay's master tempo can be synced to the tempo of a VST host application when running under VST. In addition, the three matrices can be automated using MIDI continuous controllers and will generate controller data when you tweak their controls manually. The program's MIDI implementation is thorough and allows everything from Effect Bypass to Mod Source Select to remote control of the matrices' settings. The comprehensive set of MIDI options adds a whole new dimension to the program's overall usability. Simultaneously automating such varied parameters as the Filter Matrix, LFO Mod Depth, and Feedback levels independently of each other, particularly with a sequencer, produces some amazing results.

INS AND OUTS

The File Player, found below the Input Modulation section, is handy. It allows you to load a preexisting sound file (WAV or AIFF on both platforms and Sound Designer II on the Mac) into RAM and play it through the program in One-Shot or Looped mode. That was the first thing I tried when I installed the program — I was curious to hear how some of the samples from my sound library would be transformed. The results were interesting, though largely dependent on the source sample and the program settings.

Spektral Delay's File Panel is intended to demonstrate the program's features through the use of sound files installed automatically from the CD. Every time I tried to invoke the File Panel, however, the program appeared to hang. Native Instruments says that was a known bug in version 1.0 that has been fixed.

Running the standalone version, you can record Spektral Delay's output to disk using the File Recorder, found at the lower-right edge of the window. (In the plug-in version, you can route the output to your VST mixer or effects.) The Recorder supports the same formats as the Player. Like all Spektral Delay functions, the Recorder's performance was sluggish on my Power Computing clone. According to the manufacturer, you will get much better performance with a native Power Mac G3 or G4, thanks to the newer computers' faster RAM and system bus.

SONIC BEHAVIOR

It is difficult to sum up the sonic quality of Spektral Delay, but some adjectives that come to mind include watery, psychedelic, otherworldly, and complex. As with any delay system that includes feedback and long delay times, it's easy to obtain spaced-out results. However, the program's highly controllable frequency parameters set it apart from the others. You could easily configure a process in which the middle frequencies arrive later than the highs while the highs feed back endlessly, for example. The ability to rearrange various frequencies of a sound over time and to alter their behavior makes it easy to animate even fairly static source material.

The modulation capabilities of Spektral Delay make it possible for nearly all of the program's parameter values to be constantly changing — it doesn't take much of an imaginative leap to see where that might lead. Although I found the character of the program's sonic texture somewhat similar to that of some Steinberg GRM Tools plug-ins, particularly the GRM Tools equalizer and filter, Spektral Delay really does sound like itself more than anything else.

Overall, Spektral Delay is an amazing tool. I found it easy to create endlessly varying psychedelia and soundscapes using a wide range of input sound material. The possibilities afforded by the editors in conjunction with the modulation and MIDI control capabilities are staggering. The File Recorder makes the program viable as a standalone application and is incredibly useful for capturing magic moments while twiddling parameters. Be warned, however: you'll be happiest using a truly fast machine; like all Native Instruments' software, Spektral Delay is quite CPU-intensive. Nevertheless, this one is a must-hear.

Peter Freemanis a bassist, composer, and producer in New York. He has worked with such artists as Seal, John Cale and Chris Spedding, Jon Hassell, Nile Rodgers, Sussan Deyhim, and Shawn Colvin.